The following definitions and those in chapter 182-500 WAC apply to this chapter.

"Adult family home" - A residential home licensed to care for up to six residents that provides rooms, meals, laundry, supervision, assistance with activities of daily living, and personal care. In addition to these services, some homes provide nursing or other special care and services.

"Apnea" - The cessation of airflow for at least ten seconds.

"Apnea-hypopnea index (AHI)" - The average number of episodes of apnea and hypopnea per hour of sleep without the use of a positive airway pressure device. For purposes of this chapter, respiratory effort related arousals (RERAs) are not included in the calculation.

"Arterial PaO2" - Measurement of partial pressure of arterial oxygen.

"Authorized prescriber" - A health care practitioner authorized by law or rule in the state of Washington to prescribe oxygen and respiratory care equipment, supplies, and services.

"Base year" - As used in this chapter, means the year in which the respiratory care medicaid provider guide's current fee schedule is adopted.

"Bi-level respiratory assist device with backup rate" - A device that allows independent setting of inspiratory and expiratory pressures to deliver positive airway pressure (within a single respiratory cycle) by way of tubing and a noninvasive interface (such as a nasal or oral facial mask) to assist spontaneous respiratory efforts and supplement the volume of inspired air into the lungs. In addition, these devices have a timed backup feature to deliver this air pressure whenever sufficient spontaneous inspiratory efforts fail to occur.

"Bi-level respiratory assist device without backup rate" - A device that allows independent setting of inspiratory and expiratory pressures to deliver positive airway pressure (within a single respiratory cycle) by way of tubing and a noninvasive interface (such as a nasal, oral, or facial mask) to assist spontaneous respiratory efforts and supplement the volume of inspired air into the lungs.

"Blood gas study" - For the purposes of this chapter, is either an oximetry test or an arterial blood gas test.

"Boarding home" - Adult residential care (ARC) facility, enhanced adult residential care (EARC) facility, or assisted living (AL) facility.

"Central sleep apnea (CSA)" - Is defined as:

(1) An apnea-hypopnea index (AHI) greater than or equal to five; and

(2) Central apneas/hypopneas greater than fifty percent of the total apneas/hypopneas; and

(3) Central apneas or hypopneas greater than or equal to five times per hour; and

(4) Symptoms of either excessive sleepiness or disrupted sleep.

"Chronic obstructive pulmonary disease (COPD)" - Any disorder that persistently obstructs bronchial airflow. COPD mainly involves two related diseases: Chronic bronchitis and emphysema. Both cause chronic obstruction of air flowing through the airways and in and out of the lungs. The obstruction is generally permanent and worsens over time.

"Complex sleep apnea (CompSA)" - A form of central apnea specifically identified by the persistence or emergence of central apneas or hypopneas, upon exposure to CPAP or a bi-level respiratory assist device without a back-up rate feature, when obstructive events have disappeared. These clients have predominantly obstructive or mixed apneas during the diagnostic sleep study occurring at greater than or equal to five times per hour. With use of a CPAP or bi-level respiratory assist device without a back-up rate feature, the client shows a pattern of apneas and hypopneas that meets the definition of central sleep apnea (CSA).

"Continuous positive airway pressure (CPAP)" - A single-level device which delivers a constant level of positive air pressure (within a single respiratory cycle) by way of tubing and an interface to assist spontaneous respiratory efforts and supplement the volume of inspired air into the lungs.

"Dependent edema" - Fluid in the tissues, usually ankles, wrists, and the arms.

"Emergency oxygen" - The immediate, short-term administration of oxygen to a client who normally does not receive oxygen, but is experiencing an acute episode which requires oxygen.

"Erythrocythemia" - More hematocrit (red blood cells) than normal.

"FIO2" - The fractional concentration of oxygen delivered to the client for inspiration. For the purpose of this policy, the client's prescribed FIO2 refers to the oxygen concentration the client normally breathes when not undergoing testing to qualify for coverage of a respiratory assist device (RAD). That is, if the client does not normally use supplemental oxygen, their prescribed FIO2 is that found in room air.

"FEV1" - The forced expired volume in one second.

"FVC" - The forced vital capacity.

"Group I" - Clinical criteria, set by medicare, to identify chronic oxygen clients with obvious respiratory challenges as evidenced by low oxygen saturation. The clinical criteria for Group I include any of the following:

• An arterial PaO2 at or below fifty-five mm Hg or an arterial oxygen saturation (SaO2) at or below eighty-eight percent taken at rest (awake); or

• An arterial PaO2 at or below fifty-five mm Hg, or an arterial oxygen saturation at or below eighty-eight percent for at least five minutes taken during sleep for a client who demonstrates an arterial PaO2 at or above fifty-six mm Hg or an arterial oxygen saturation at or above eighty-nine percent while awake; or

• A decrease in arterial PaO2 more than ten mm Hg, or a decrease in arterial oxygen saturation more than five percent from baseline saturation for at least five minutes taken during sleep associated with symptoms (e.g., impairment of cognitive processes and nocturnal restlessness or insomnia) or signs (e.g., cor pulmonale, "P" pulmonale on EKG, documented pulmonary hypertension and erythrocytosis) reasonably attributable to hypoxemia; or

• An arterial PaO2 at or below fifty-five mm Hg or an arterial oxygen saturation at or below eighty-eight percent, taken during exercise for a client who demonstrates an arterial PaO2 at or above fifty-six mm Hg or an arterial oxygen saturation at or above eighty-nine percent during the day while at rest. In this case, oxygen is provided during exercise if it is documented that the use of oxygen improves the hypoxemia that was demonstrated during exercise when the client was breathing room air.

"Group II" - Clinical criteria, set by medicare, to identify borderline oxygen clients. Their blood saturation levels seem to be within the normal range, but there are additional extenuating issues that suggest a need for oxygen. The clinical criteria for Group II include any of the following:

• The presence of an arterial PaO2 of fifty-six to fifty-nine mm Hg or an arterial blood oxygen saturation of eighty-nine percent at rest (awake), during sleep for at least five minutes, or during exercise (as described under Group I criteria); and

• Any of the following:

– Dependent edema suggesting congestive heart failure; or

– Pulmonary hypertension or cor pulmonale, determined by measurement of pulmonary artery pressure, gated blood pool scan, echocardiogram, or "P" pulmonale on EKG (P wave greater than three mm in standard leads II, III, or AVF); or

– Erythrocythemia with a hematocrit greater than fifty-six percent.

"Home and community residential settings" - In-home, adult family home, or boarding home.

"Hypopnea" - A temporary reduction of airflow lasting at least ten seconds and accompanied with a thirty percent reduction in thoracoabdominal movement or airflow as compared to baseline, and with at least a four percent decrease in oxygen saturation. The AHI is the average number of episodes of apnea and hypopnea per hour of sleep without the use of a positive airway pressure device.

"Hypoxemia" - Less than normal level of oxygen in the blood.

"Maximum allowable" - The maximum dollar amount the medicaid agency reimburses a provider for a specific service, supply, or piece of equipment.

"Month" - For the purposes of this chapter, means thirty days.

"Nebulizer" - A medical device which administers drugs for inhalation therapy for clients with respiratory conditions such as asthma or emphysema.

"Obstructive sleep apnea (OSA)" - This syndrome refers to the interruption of breathing during sleep, due to obstructive tissue in the upper airway that collapses into the air passage with respiration.

"Oxygen" - Medical grade liquid or gaseous oxygen.

"Oxygen concentrator" - A medical device that removes nitrogen from room air and retains almost pure oxygen (eighty-seven percent to ninety-five percent) for delivery to a client.

"Oxygen system" - All equipment necessary to provide oxygen to a client.

"Portable oxygen system" - A system which allows the client to be independent of the stationary system for several hours, thereby providing mobility for the client.

"Pulmonary hypertension" - High blood pressure in the vessels that feed through the lungs, causing the right side of the heart to work harder to oxygenate blood.

"Respiratory care" - The care of a client with respiratory needs and all related equipment, oxygen, services, and supplies.

"Respiratory care medicaid provider guide" - A manual containing procedures for billing, which is available online at http://maa.dshs.wa.gov/download.

"Respiratory care practitioner" - A person licensed by the department of health according to chapter 18.89 RCW and chapter 246-928 WAC as a respiratory therapist (RT) or respiratory care practitioner (RCP).

"Respiratory effort related arousals (RERA)" - These occur when there is a sequence of breaths that lasts at least ten seconds, characterized by increasing respiratory effort or flattening of the nasal pressure waveform, which lead to an arousal from sleep. However, they do not meet the criteria of an apnea or hypopnea.

"Restrictive thoracic disorders" - This refers to a variety of neuromuscular and anatomical anomalies of the chest/rib cage area that may result in hypoventilation, particularly while the client sleeps at night.

"Reasonable useful lifetime (RUL)" - For thirty-six month capped oxygen equipment, the RUL is five years. The RUL is not based on the chronological age of the equipment. It starts on the initial date of the rental and runs for five years from that date.

"Stationary oxygen system" - Equipment designed to be used in one location, generally for the purpose of continuous use or frequent intermittent use.